1. Field of the Invention
The present invention relates to a mark retaining structure of a micro-differential pressure gauge, in particular to a mark attachment structure for a pointer gauge.
2. Description of the Prior Art
A conventional gauge, such as a micro-differential pressure gauge or a pressure gauge, includes a pointer therein. The pointer is rotated according to the pressure. In conjunction with a numeral scale plate in the gauge, the user can read the value. In general, the gauge is set with a security value. For the user to know whether or not the pointer is in the range of safety, the gauge is provided with a safety mark. The inventor of the present application has an idea that the retaining way should be simplified for a convenient operation and the positioning effect should be improved. Accordingly, the inventor of the present invention has devoted himself based on his many years of practical experiences to solve this problem.